Chaps:

 

What can cause this? Cause I seem to have it :-(

 

/\/\ark

 

Detonation!

 

Your knocking sensor has noticed some knocking and placed it into safety mode. This sensor works below 3K revs so it notices it and enables safety boost before you even have a chance to hear it. You might have a crap tank of fuel. This is very common when purchasing fuel from 'cheepo' garages. Run it out and purchase fuel from a premium garage.

 

If that fails then its a process of elimination. If you are using 95 unleaded, give 97 super a try. Spark plugs are usually the next culprit. Check them ensuring gaps are correct. Clean knocking sensor connectors. Check timing etc. At this stage its a good idea to take it to a Z specialist. Timing/mixture and so forth can be checked at set up accordinly. Also, it might just be that the knocking sensor is faulty. This is a FPITA to change and will require the sale of your house for the labour costs. But, there are simple ways to overide it , you just need a careful ear so you can notice detonation yourself.

 

Good luck!

 

Andy.

 

 

Mark,

 

Check your ecu for any error codes.

 

I think error 34 is the knock sensor.

 

If the ecu has error 34 then it maintains the stock boost control solenoids in the 'ON' position which means that your turbo's will only make 7psi.

 

It's engine out to change the detonation sensor but there is a way to overide it!

 

H Le Hir has tech page somewhere on how it's done.

 

Steve

 

Thanks chaps:

 

Gotta find the time to check all this out...

 

Its running SuperPlus. Strange thing is it was boosting fine (120 along a bypass) stopped for roundabout then ready for the next blast and... nothing, 7psi as you say :-( not good.

 

Also, gotta strange oil pressure problem - on idle sometimes (only sometimes) its dropping very close to (but not quite) nowt!

 

Whats FPITA?

 

Cheers

 

/\/\ark

 

 

Mark,

 

Most 300's have a problem with the reading on the oil pressure gauge.

 

Normally a new oil pressure sender cures this problem and cost about £35 from Courtesy.

 

Best time to fit it is when the next oil change is due.

 

If it isn't the sender and you have a genuine oil presure problem, you can find out the easy way by giving it 7000rpm in 3rd gear.

 

If the engine goes bang then it is a pressure problem and this way you would save £35 for a new sender - LOL

 

Steve

 

Okay:

 

This gets stranger....

 

Went for a blast yesterday... no oil pressure problems... and BOOSTED to 10 or 11 psi!!!!

 

Any ideas?

 

/\/\ark

 

Yep, you have an intermittent fault! LOL

 

 

Drive it around and see how it goes. If it happens again then do what steve suggested and get a Consult test done. The best way is to drive around with the consult plugged in until the fault shows up then the consult will record it.

 

Andy

 

Mark,

 

The two issues are not related.

 

My oil pressure gauge is the same, one day it's at 30psi at idle and the next it sits on zero!

 

With the safety boost issue, every time you shut off the engine, the ecu resets itself.

 

When you restart, everything is fine and you will get full boost until the detonation sensor tells the ecu to activate the safety boost again.

 

In my previuos post, I meant to say that the stock solenoids stay in the 'OFF' position during safety boost and this means you can only reach 7psi.

 

This is because the wastegates are spring actuated and if the solenoid doesn't control them this then they will automatically open and 7psi and hence no more boost can be made.

 

Steve

 

Thanks again chaps:

 

Re: Consult - anyone have a spare one I can drive around with till the fault occurs ;-)

 

Re: boost - my gauge goes from -14psi to +14psi. what should it boost to (stock +intake + exhaust)?

 

/\/\ark

 

Mark,

 

I think your needle should run to about 3/4 on the gauge which is 9psi maybe a bit more.

 

The stock gauages are renouned for being inaccurate but as long as your not running past the +14psi.

 

Steve

 

 

When I had intake & exhaust, my needle would go to the next to last line on the gauge (10psi?).

Probably nowehere near that in reality.

Dave

 

Yep - sounds bout right.

 

Its not done it since (safety boost)! I wonder if its a dodgy sensor/componenet thats shown itself due to the temperature (we had a hot day here on Friday when it happened - its been relatively cool since and hasnt happened again)? Its gonna be a long time before I can put this theory to the test (two hot days in th same year in the uk - lol)!

 

Thanks for your help guys - I think now it a case of 'run as many diags & test as many sensors & components as I can' - no mirracle instant fix :-(

 

Cheers

/\/\ark

 

 

 

i know what the problem is m8ty. ure mean machine has seen the beast from the east and is now shaking in fear as it now has some competition in the ice and styling stakes lol

 

heheheheheh

 

take it easy m8ty